rs74533482

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_020822.3(KCNT1):​c.3685A>G​(p.Thr1229Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000801 in 1,605,654 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00055 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00083 ( 3 hom. )

Consequence

KCNT1
NM_020822.3 missense

Scores

2
17

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:11

Conservation

PhyloP100: 4.60
Variant links:
Genes affected
KCNT1 (HGNC:18865): (potassium sodium-activated channel subfamily T member 1) Potassium channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. This gene encodes a sodium-activated potassium channel subunit which is thought to function in ion conductance and developmental signaling pathways. Mutations in this gene cause the early-onset epileptic disorders, malignant migrating partial seizures of infancy and autosomal dominant nocturnal frontal lobe epilepsy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2012]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -20 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.032767117).
BP6
Variant 9-135792138-A-G is Benign according to our data. Variant chr9-135792138-A-G is described in ClinVar as [Likely_benign]. Clinvar id is 378038.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.000553 (84/151986) while in subpopulation NFE AF= 0.00112 (76/67964). AF 95% confidence interval is 0.000916. There are 0 homozygotes in gnomad4. There are 40 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
BS2
High AC in GnomAd4 at 84 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNT1NM_020822.3 linkc.3685A>G p.Thr1229Ala missense_variant Exon 31 of 31 ENST00000371757.7 NP_065873.2 Q5JUK3-3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNT1ENST00000371757.7 linkc.3685A>G p.Thr1229Ala missense_variant Exon 31 of 31 1 NM_020822.3 ENSP00000360822.2 Q5JUK3-3

Frequencies

GnomAD3 genomes
AF:
0.000553
AC:
84
AN:
151868
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000726
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000328
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00112
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000498
AC:
120
AN:
240930
Hom.:
0
AF XY:
0.000464
AC XY:
61
AN XY:
131498
show subpopulations
Gnomad AFR exome
AF:
0.000190
Gnomad AMR exome
AF:
0.0000583
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00103
Gnomad OTH exome
AF:
0.000168
GnomAD4 exome
AF:
0.000827
AC:
1202
AN:
1453668
Hom.:
3
Cov.:
32
AF XY:
0.000834
AC XY:
603
AN XY:
723386
show subpopulations
Gnomad4 AFR exome
AF:
0.0000896
Gnomad4 AMR exome
AF:
0.0000448
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00106
Gnomad4 OTH exome
AF:
0.000398
GnomAD4 genome
AF:
0.000553
AC:
84
AN:
151986
Hom.:
0
Cov.:
32
AF XY:
0.000538
AC XY:
40
AN XY:
74298
show subpopulations
Gnomad4 AFR
AF:
0.0000724
Gnomad4 AMR
AF:
0.000327
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00112
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000906
Hom.:
0
Bravo
AF:
0.000540
TwinsUK
AF:
0.000809
AC:
3
ALSPAC
AF:
0.00156
AC:
6
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000698
AC:
6
ExAC
AF:
0.000511
AC:
62
Asia WGS
AF:
0.000289
AC:
2
AN:
3478
EpiCase
AF:
0.00131
EpiControl
AF:
0.000535

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:11
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:5
Oct 09, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

-
Breakthrough Genomics, Breakthrough Genomics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: not provided

- -

Apr 24, 2018
GeneDx
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jul 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

KCNT1: BP4, BS1 -

May 11, 2017
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Developmental and epileptic encephalopathy, 14;C3554306:Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:2
Jan 24, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Mar 30, 2021
Center for Genomics, Ann and Robert H. Lurie Children's Hospital of Chicago
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

KCNT1 NM_020822.2 exon 31 p.Thr1229Ala (c.3685A>G): This variant has not been reported in the literature but is present in 0.1% (72/64504) of European alleles in the Genome Aggregation Database (https://gnomad.broadinstitute.org/variant/9-135792138-A-G?dataset=gnomad_r3). This variant is present in ClinVar, with several labs classifying this variant as likely benign (Variation ID: 378038). Evolutionary conservation for this variant is unclear; computational predictive tools suggest that this variant may not impact the protein. In summary, data on this variant suggests that this variant does not cause disease, but requires further evidence. Therefore this variant is classified as likely benign. -

Inborn genetic diseases Benign:1
Sep 15, 2018
Ambry Genetics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

KCNT1-related disorder Benign:1
Feb 16, 2022
PreventionGenetics, part of Exact Sciences
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Developmental and epileptic encephalopathy, 14 Benign:1
Mar 15, 2022
Genome-Nilou Lab
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Autosomal dominant nocturnal frontal lobe epilepsy 5 Benign:1
Mar 15, 2022
Genome-Nilou Lab
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.094
BayesDel_addAF
Benign
-0.43
T
BayesDel_noAF
Benign
-0.39
CADD
Benign
20
DANN
Benign
0.93
DEOGEN2
Benign
0.043
.;.;.;.;.;.;.;.;T;.
Eigen
Benign
-0.21
Eigen_PC
Benign
-0.12
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.81
T;T;T;T;T;T;T;T;T;T
M_CAP
Benign
0.040
D
MetaRNN
Benign
0.033
T;T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
0.81
.;.;.;.;.;.;.;.;L;.
PrimateAI
Uncertain
0.51
T
PROVEAN
Benign
-1.1
.;.;N;.;.;.;.;.;.;N
REVEL
Benign
0.14
Sift
Benign
0.075
.;.;T;.;.;.;.;.;.;T
Sift4G
Benign
0.20
T;T;T;T;T;T;T;T;T;T
Vest4
0.60
MVP
0.44
MPC
0.090
ClinPred
0.026
T
GERP RS
4.7
Varity_R
0.093
gMVP
0.54

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs74533482; hg19: chr9-138683984; API